var downPdf = document.getElementById("exportToPdf");

downPdf.onclick = function () {
    makePdf();
}

function makePdf() {
    document.getElementById("button").style.visibility="hidden";
    $('.right-div').css({
        'overflow-y': 'visible',
        'height': 'auto'
    });
    let export_content = $('#print');
    let copyDom = $('<div/>');
    copyDom.addClass('super');
    copyDom.width(export_content.width() + 'px');
    copyDom.height(export_content.height() + 'px');
    $('body').append(copyDom);
    var ST = document.documentElement.scrollTop;
    var SL = document.documentElement.scrollLeft;
    document.documentElement.scrollLeft = 0;
    document.documentElement.scrollTop = 0;
    html2canvas(
        document.getElementById("print"),
        {
            dpi: 1050,//导出pdf清晰度
            onrendered: function (canvas) {
                document.documentElement.scrollTop = ST;
                document.documentElement.scrollLeft = SL;
                var contentWidth = canvas.width;
                var contentHeight = canvas.height;
                //一页pdf显示html页面生成的canvas高度;
                var pageHeight = contentWidth / 592.28 * 841.89;
                //未生成pdf的html页面高度
                var leftHeight = contentHeight;
                //pdf页面偏移
                var position = 0;
                //html页面生成的canvas在pdf中图片的宽高（a4纸的尺寸[595.28,841.89]）
                var imgWidth = 595.28;
                var imgHeight = 592.28 / contentWidth * contentHeight;
                var pageData = canvas.toDataURL('image/jpeg', 1.0);
                var pdf = new jsPDF('', 'pt', 'a4');
                //有两个高度需要区分，一个是html页面的实际高度，和生成pdf的页面高度(841.89)
                //当内容未超过pdf一页显示的范围，无需分页
                if (leftHeight < pageHeight) {
                    pdf.addImage(pageData, 'JPEG', 0, 0, imgWidth, imgHeight);
                } else {
                    while (leftHeight > 0) {
                        pdf.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight)
                        leftHeight -= pageHeight;
                        position -= 841.89;
                        //避免添加空白页
                        if (leftHeight > 0) {
                            pdf.addPage();
                        }
                    }
                }
                pdf.save('儿童生长发育评估报告.pdf');
                $('.super').remove();
                $('.right-div').css({
                    'overflow-y': 'auto',
                    'height': '100%'
                });
            },
            //背景设为白色（默认为黑色）
            background: "#fff"
        })
    document.getElementById("button").style.visibility="visible";
}




